<p>Identification and qualification of reusable software based on software models and metrics is explored. Software metrics provide a way to automate the extraction of reusable software components from existing systems, reducing the amount of code that experts must analyze. Also, models and metrics permit feedback and improvement to make the extraction process fit a variety of environments. Some case studies are described to validate the experimental approach. They deal with only the identification phase and use a very simple model of a reusable code component, but the results show that automated techniques can reduce the amount of code that a domain expert needs to evaluate to identify reusable parts.</p>